In the fields of pharmaceutical products, foods and health foods, the method for producing a solid preparation, especially a tablet, includes dry direct tableting in which a mixture of a drug and an additive is directly subjected to tableting; dry granulation tableting in which a mixture of a drug and an additive is subjected to roll compression (dry granulation), then disintegration and tableting; and wet granulation tableting in which a mixture of a drug and an additive is granulated together with a binder solution or an appropriate solvent such as water, and the resulting granules are dried and then subjected to tableting. The wet granulation tableting involves an agitation granulator or a fluidized bed granulator.
The dry direct tableting and the dry granulation tableting have been increasingly adopted in many cases because the methods are applicable to a drug susceptible to water and include a simple process for easy process control. However, the methods typically require a larger amount of an additive than the wet granulation tableting in order to ensure moldability. Examples of the additive having high moldability include crystalline cellulose (JP 06-316535A), hydroxyalkyl cellulose fine particles (WO 2011/065350A1) and low-substituted hydroxypropyl cellulose (JP 2010-254756A).
In recent years, tablets are downsized for easy administration, so that the content of a binder or the like is likely to be suppressed. To address such a trend, there is a demand for a binder that increases the hardness of a tablet at a small content. In addition, a tablet administered is desired to be immediately disintegrated in terms of bioavailability.